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G. CAMERON.

SELECTIVE INTERLOCKING SWITCH MECHANISM.

APPLICATION FILED OCT. 5. 1912.

2 SHEETS-SHEET l- ,32 L64O. Patented Dec. 9, 1919.

G. CAMERON.

SELECTIVE INTERLOCKING SWITCH MECHANISM.

APPLICATION FILED OCT. 5. m1.

1 ,324:,640. Patented Dec. 9, 1919.

2 SHEETS-SHEET 2.

UITE sTA'rEs PATENT oFFicn GORDON CAMERON, 0E FIOLLA'STCN, MASSACHUSETTS, ASSIGNOR T0 SEARS B. CONDIT, JR., 0F BROOKLINE, MASSACHUSETTS.

SELECTIVE INTERLOCKING SWITCH MECHANISM.

To all whom it may concern:

Be it known that I, GORDON CAMERON, a subject of the King of England, residing at WVollaston, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Selective Interlocking Switch Mechanism, of which the following is a specification.

My invention relates to electric switches in which a series of switches are to be operated in a certain predetermined successive order, and has for its object the provision of suitable selective interlocking mechanism associated with the switch operating members; whereby all of the switches in the series, with the exception of a predetermined switch, will be locked in open position; whereby the switches in the series can be operated only in a progressive order, beginning at one predetermined switch, and whereby all of the unoperated switches of the series, and the previously operated switch, will be locked in open position. A

The mechanism by means of which the selective interlocking of the switch operating members is obtained consists of a shaft extending between two adjacent switch operating members and provided, at its ends, with cams, the faces of which are adapted to engage parts of the switch operating handles tolock either one or the other of the two switch operating members in open or closed position,and a separate cam carried bythe shaft adapted to be engaged by a latch, in its depressed position, carried by the handle of a switch operating member, whereby, uponthe movement of the handle to open position with depressed latch, the cam shaft will be caused to rotate to selectively operate the interlocking mechanism.

Figure 1 illustrates the interlocking mechanism applied to a series of switch operating members.

Fig. 2 is a diagrammatic side elevation of the relative position of cams and switch handles with locking mechanism in normal position.

Fig. 3v is a fragmentary side elevation of a switch m ember and associated cams with switch handle in closed position.

Fig. 4 is a view of Fig.3 with switch handle in open position.

as Fig. .5 s 'a. frag entary ide el vation of Specification of Letters Patent.

Application filed October 5, 1917.

Patented Dec, 9, 1919. Serial No. 194,959.

the second switch member, showing the position of the locking cam with switch handle in open position.

Fig. 6 is a plan view of the cam shaft and supporting brackets.

As here shown, the interlocking mechanism is applied to the face plates of two oil switches which are designed to be mounted in line on a switch panel, and to have rods passing through the panel for engagement with the switch handles carried by the face plates and with the switch members in the switch casings.

The face plates 1 and 2 have switch op erating handles 3 and 4, pivoted at 5 and 6 to the respective face plates. The switch operating rods 7 and 8 are pivoted to the handles 5- and 6 at points intermediate the length of the handles and pass through the face plates and make mechanical connection with the switch members, not shown.

Each handle 3 and 4 has a latch 9 secured to a member 10 and arranged to slide in a slot 11 of handles 5 and 6. The member 10 is supported by handles 5 and 6,'and is secured, at its upper end to a rod 12 which passes through the handle and terminates in a thumb-button 12. The thumb button 12 is normally maintained in a protruding position from handles 3 and 4 by a spring 13, and consequently latch 9 is maintained against the upper end of slot 11. Brackets 14 are secured to face plates 1 and 2 and cam shaft 15 is journaled in these brackets. A cam 16 is fixed to the end of shaft 15 adjacent face plates 2, and two cams 17 and 18 are fixed to the end of shaft 15 adjacent face plate 1.

A block 19 is fixed to shaft 15 and is proyided with a face 20. A pin 21, slidably secured to extension 22 of bracket 14 of face plate 1, is continually pressed against this face 20 by the action of a spring 23, and tends to normally maintain an edge of block 19 against a plug 24 secured in extension 22, and to maintain the cams 16, 17, and 18 in the normal position shown in Fig. 2.

Cam 16, in this normal position, interposes a face 25 in the path of movement of pin 26 secured to handle 4, and thus prevents a movement of handle 4 to closed position. Cam 17, associated with handle 3 of face plate 1, in the normal position of cam shaft 15 is removed from the path of movement of pin 27 securedto handle 3, andpe'rmits the movement of handle 3 to closed position. In the closed position of the handle, the latch 9 engages a notch 28 in a projection 29 from face plate-1. Latch 9 is so disposed as not to engage cam 18 on a closing movement of the handle 3.

When handle 3 is to be moved to open position, thumb button 12 is depressed and latch 9 correspondingly depressed in slot 11, to clear notch 28. Upon movement of handle 3 to open position, with latch 9 in its depressed position, said latch 9 engages a face of cam 18 and rotates cam 18 and consequently shaft 15 against pressure of spring 23, acting against pin 21. Rotation of shaft 15 serves .to rotate the face of cam 16 from the path of movement of pin 26 secured to handle 4:, and permits the movement of handle 4 to closed position. In the closed position of the handle 4, pin 26 engages a face of cam 16, and restrains the cam 16 from a return movement under action of spring 23.

The rotation of cam shaft 15 by the engagement of latch 9 with cam 18, also serves to move cam 17 to a position in the path of travel of pin 27 of handle 3, and, therefore, prevents a movement of handle 3 to closed position, any forces acting on cam 17 tending to rotate it in the reverse direction being resisted by the engagement of pin 26 of handle el and cam 16. Handle 3 is thus locked against a closing movement while handle 1 is in closed position upon the movement of handle 4 to open position, and the consequent disengagement of pin 26 with the face 30 of cam 16, cam 16 and shaft 15 are rotated to normal position under action of spring 23, and face 25 of cam 16 is interposed in the path of movement of pin 26 of switch operating handle 4:. The return of shaft 15 to normal position also rotates cam 17 away from path of movement of pin 27 of handle 3, thus permitting handle 3 to be moved to closed position.

If handle 3 is moved to open position and thumb button 12, and consequently latch 9, is released'before the handle 4 is moved to closed position, then the release of latch 9 i from engagement of the face of cam 17 will permit cam 17 and shaft 15 to return to normal position, thus interposing face 25 of cam 16 in the path of movement of pin 26 of handle 4, and thus preventing movement of handle 4 into closed position.

It is thus seen that, with switch handles 3 and 4 in open position, handle 4 cannot be closed, but upon the closing and subsequent opening of handle 3 with depressed latch, iandle 4 may be closed and handle 3 locked against closing. With the subsequent opening of handle 4, the interlocking mechanism returns to normal original position with handle 4 locked against closing.

In the control of electrical devices requiring more than two switches, the cam shaft 15, with cams 16, 17, and 18 are duplicated between each two face plates or switch op-' erating members. In the arrangement shown in Fig. 1, but extended to include more than two face plates, every handle but the left-hand one will be locked in open position; the closing of this left handle and its subsequent opening with depressed latch will permit the closing of the first righthand switch member, and the closing of this switch locks the previously operated switch handle in open position. The opening. of the first right-hand switch will permit the closing of the second ri ht-hand switch, and lock the first rightand or previously-operated switch, and so on through the series.

Only one switch can be operated at one time, and the series of switches can be operated only in a predetermined successive order.

I claim 1. Selective-interlocking switch-operating mechanism, comprising a plurality of electric switch operators, cams normally interposed in the path of movement of all of said operators except an initial operator to lock all of said operators except the initial operator in open position, and means controlled by the opening of the initial operatorto move said cam from the path of movement of said next succeeding operator to per-' mit the closing movement of said operator.

Selective-interlocking switch-operating mechanism, comprising a plurality of electric switch operators, cams normally interposed in the path of movement of all of said operators except an initial operator to lock all of said operators except the initial operator in open position, and means adapted to be engaged by a part of the initial opera,- tor in its movement thereof to open position, to move said cam from the path of movement of said next succeeding operator to. permit the closing movement of said operator.

3. Selective-interlocking switch-operating mechanism, comprising a plurality of elec- V tric switch operators, cams normally interposed in the path of movement of all of said operators except an initial operator to look all of said operators except the initial operator in open position, and means controlled by the opening of the initial operator to move said cam from the path of movement of said next succeeding operator to permit the closing of said operator, and to also move a cam in the path of movement of said initial operator, and to maintain said cam in set position by closed position of said first succeeding operator to lock said initial operator in open position.

4. Selective-interlocking switch-operating if mechanism, comprising a plurality of electric switch operators, a cam shaft, cams arranged thereon, said cam shaft and cams being so associated with said operator as to normally lock all of said operators except an initial operator in open position, other cams carried by said cam shaft, means associated with said cam shaft operable by the opening of the initial operator to rotate said cam shaft tomove one of said cams from the path of movement of the first succeeding operator to unlock said operator, and to move one of said cams in the path of movement of said initial operator whereby said initial operator will be locked in open position in the closed position of the first succeeding operator.

5. Selective-interlocking switch-operating -mechanism, comprising a plurality of electric switch operators, a cam shaft, cams arranged thereon, said cam shaft and cams arranged to normally look all of said operators except an initial operator in open position, other cams carried by said cam shaft, one of the cams carried by said cam shaft being adapted to be engaged by a part of the initial operator during its movement thereof to open position to rotate said cam shaft to move one of said cams from the path of movement of the first succeeding operator to thereby unlock said operator, and also to move one of said cams in the path of movement of said initial operator whereby said initial operator will be locked in open position in the closed position of the first succeeding operator.

Selective-interlocking switch-operating mechanism, comprising a plurality of electric switch operators, a cam shaft, cams arranged thereon, said cam shaft and cams arranged to normally look all of said operators except an initial operator in open position, other cams carried by said cam shaft, one of the cams carried by said cam shaft being adapted to be engaged by a manuallycontrolled part of the initial switch during its movement thereof to open position to rotate said cam shaft to move one of said cams from the path of movement of the first succeeding operator to thereby unlock said operator, and also to move one of said cams in the path of movement of said initial operator whereby said initial operator will be locked in open position in the closed position of the first succeeding operator.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

GORDON CAMERON. 

